Electrical recording apparatus



Aug. 19, 1930. H. w. ROGERS 1,773,501

ELECTRICAL RECORDING APPARATUS Filed Dec. 13. 1926 Petented Aug. 19.19 36 water UNITED STATES PATENT OFFICE HARRISON w. Room, or imw YORK, n. Y.

- mnemonnncoanme nr'rm'rus Application. mm December'13, 1926. s m n. 154,680.

This invention relates to im rovements in electrical sound recording an reproducing apparatus whereby the electromagnetic means is employed to influence a stylus actu '5 ated member,or be influenced thereby,

cially adapting the present invention or making records of any character of sound for use in sound reproducing machines separably or in conjunction with motion picture cameras 32d projectors and for producing such soun ' Aiurther object of this invention is the provision of a polarized magnetic device in which there is practicall no mechanical re- 16 bound or oscillation of t e armature to produce irregular lines in forming the sound groove but which will only form the groove directly as influenced by the sound. In the accompanying drawings Eigurel is a side elevation ofothe complete device. Y i

Figure 2 is an end view of the magnets and associated armature, coils and stylus carrymi member. 26 igure 3 is a detail view of the stylus carrying member per se. a

a Figure 4 is a view of a modified form of recorder-reproducer.

' The present type of pick-up is of the type so iii which two permanent magnets 5 and 5', are

supported in a swingingly mounted casing A;

k which latter casing is attached by-set screws t to the fulcrumin rod a, rotatably mounted transversely of t e carrying hollow arm B, which as is customary ismounted for lateral swinging movements. A rod C-extends from the god a grind out of tlie iarmB, carrying an a, justa e counter a ancl'ng weight a, through the med of which the ac pressure of the stylus may be regulated relatively to the sound record. 7

.The respective coils 6 and 6 a eattached to the respective magnets 5 and and are normally in a closed electrical circuit, while e5 resting upon the respective south oles 7-2' are the armatures' 8-8. Carrie bodily by ,these armatures are the respective coils 11-:- 11, which when the pick-up is in operative relation are connected in the circuit, thatin turn is connected to the first stage of an am- -tacles and plification circuit, the ends of the armatures extending above the respective. north poles of the magnets 5-5 and terminating in spaced relation to each other, and so as to receive and en port between such free ends the stylus carrymg member 10, there being coacting recepintles 9 formin such support, a and permitting the rocking o thestylus carrying member laterall due to'the action of the phonic groove of t e disc record, and so 00 that the respective armatures 8-8- will be accordin ly moved to and from the respective nort poles of magnets 5-5, and thus cause the desired efiect to be transmitted to and through the amplifying system.

Inasmuch'as the two coils 6-6 are con-' nected in an independent closed electrical cir- .cuit, and the coils 11-11 are connected in the circuit that is influenced by the recorded. sound waves or the waves thatare to be reproduced, when the device is used as a pick- 7 up, it'will be evident that the armatures will be continuously affected by the current influence through the coils 6-6, and that when the coils 6-6 are influenced by the impres 7 sions thereon through the sending or recording circuits, that-there will be a tendency to suppress the undue oscillations of the armatures and, consequently the stylus carrying member. Thus the coils 6-6 so mounted dis lace the usual braking devices, such as springs or rubbertubes usually employed to counteract undue mechanical movements in the stylus carrying member.

' From the foregoing description it will be seen that as one armature 8 is attracted thestylus 12 will be moved in one direction due to the reception of the sound when the device is used as a recorder while the opposite armature 8" will" act as a retardin -means to pre- 0 vent an undue movement of t e stylus in the impelled direction, the opposite armature when attracted effecting the stylus in the opposite direction and being retarded in a similar manner by the unattracted armature.

In Figure 4, is illustrated a modified form in a more or less diagrammatic scheme diflers ing from that shown in Figures 1 and 2, in

that the, coils 6-6, are positioned slightly difierent, but so as to have the same. influence we I ber supported b O the armatures and capable of a being oscillate by the armatures.

upon the north poles of the magnets, and consequently influence the various armatures 8--8'. The other formhowever, is preferable because of its compactness and ease of mounting, and wherein the magnets are mounted by the screws 12 and 13 carried by and to the casing A. w

This electrical pick-up may be supported as shown in Figure 1 within an end member A, pivoted at a to the tone arm B, the stylus carrying member 10 projecting thru the bottom, as shown, to engage the record face, and an extension C, with the adjustable weight 0, being provided to balance the weight of the pivoted end, said extension and weight being reached thru the aperture 6 in the tone arm. Additional adjustment between the swinging end and the extension C is provided by tension means t. Mechanical damping of the member 10 by a spring S is shown in Figure 3 and may be additional to the electrical damping described.

From the foregoing description it will be appreciated that the present device "can be used as a recording instrument as well as a reproducing or electrical pick-up for sound reproducing machines.

What I claim as new is 1. An electric recorder-reproducer, including two permanent magnets, two armatures, one to each magnet mounted with their free ends toward each other, a coil for each magnet, a coil'tarried by each armature, and a stylus carrying member. suspended between the free ends of said armatures and operated thereby, whereby the coils of the armatures are to be in an uninfluenced closed electrical -circuit while the other coils are located in a circuit to influence or to be influenced by the sound wave reproducing or recording.

2. A stylus recorder-reproducer, including two bi-polar permanent magnets, two coils, one coil being under the influence of one pole of each magnet, two armatures influenced respectively by'the coil carrying poles of said magnets, two additional C0115, one coil carried by each armature, and a stylus carrying mem- 3. A stylus recorder-reproducer, including two bi-polar permanent magnets, two coils, one coil being under the influence of one pole of each magnet, two armatures, one magnetically pivoted to the remaining "terminal of said magnets, the free ends of said armatures being toward and spaced from each other, a coilcarried b carrying mem er supported by and between the free ends of the armatures, and through which oscillatory movement is imparted to the member.

4. A stylus recorder-reproducer, including two b'i-polar permanent magnets, two coils, one to influence each permanent magnet, two

each armature, and a stylus" M arr/acct armatures pivoted, one to a pole of each magnet, the inner free ends of the armatures being spaced from each other, and a stylus carrying member pivoted between and supported by the free ends of the armatures, whereby as the armatures are simultaneously swung in opposite directions oscillatory movement is imparted'to the stylus carrying member.

5. A stylus recorder-reproducer, including two bi-polar permanent magnets, two coils, one to each magnet and under the influence of one pole of one magnet, two armatures magnetically pivoted, one to each remaining pole of the magnets, the inner ends of the armatures being spaced and toward each other, two'more coils, one carried by each armature, and a stylus carrying member pivoted be tween and supported by the 'free ends of the armatures, whereby as the armatures are simultaneously swung in opposite directions gscillatory movement is imparted to the mem- 6. A stylus recorder-reproducer, including two bi-polar permanent magnets, two coils, one to each magnet and under the influence of one pole of its magnet, two armatures, one end of each being magnetically mounted upon its respective remaining pole of the magnets, the

' free ends of the armatures being toward and spaced from each other, and in attractive relation to the coil carrying ends of the first magnet, a coil carried by each armature, and a stylus carrying arm supported between and carried by the two armatures, whereby as the armatures are simultaneously moved 1n opposite directions the arm is oscillated. a, v

.7. A stylus recorder-reproducer, including two bi-polar permanent magnets, two coils, one attached to one pole of each magnet, two armatures, supported-by two remaining poles of the two magnets and having their free ends toward and spaced from each other and in such a manner that the free end of one armature will move simultaneously with and in an opposite direction to the free end of the other armature, and a stylus carrying member operably connected to the free ends ofthe armatures, and oscillato by said armatures.

8; A stylus recor er-reproducer, including two'bi-polar permanent magnets, two coils,

one attached to one pole of each magnet,'two independent armatures, each supported by \one "magnetic pole of each magnet, and said armatures having their free ends toward and spaced from each other and in such manner that the free ends ofone armature will move in an opposite direction to the free end of the other armature, and a stylus carrying arm operablyconnected to the free ends of both 7 armatures and oscillated by said armatures.

9. A stylus recorder-reproducer, including two bi-polar permanent magnets, two coils, one attached to one pole of each magnet, two independent armatures, each supported by one magnetic pole of each magnet, and said armatures having their free ends toward and spaced from each other and in such a manner 7 that the free ends of one armature will move in an opposite direction to the free end of the other armature, a stylus carrying member operably-connected to the free ends of the armatures and oscillated b said armatures,

and a damping means for t e stylus carrying member. 7 v

10. A stylus recorder-reproducer, includin two -bi-polar permanent magnets, two cells, one attached to one pole of each magnet, two independent armatures, each one supported by one magnetic pole of each magnet,

and said armatures having their free ends toward and spaced from each other and insuch a manner that the free end of one armature will move in an opposite direction to the free 

